1. Field of the Invention
The present invention relates to a pulse generator and method thereof, and more particularly, to a pulse generator for generating a plurality of pulses and method thereof.
2. Description of the Related Art
Multiple pulses (e.g., four or more) may be used conventionally in order to control a direct current (DC) motor. Conventional micro-control units (MCUs) may include a hardware device having accessory circuits in addition to a counter circuit to generate the multiple pulses for a desired period and at a desired duty cycle.
FIG. 1A is a timing chart illustrating a conventional pulse generation method in accordance with a conventional pulse generator. FIG. 1B is a block diagram illustrating a conventional pulse generator for performing the pulse generation method of FIG. 1A.
Referring to FIGS. 1A and 1B, values representing a period and a duty cycle of a pulse may be stored in a period value storage register 11 and a duty value storage register 12, respectively. If a value of a clock signal counted by a counter is determined to be lower than the duty cycle, a higher logic pulse may be generated. Otherwise, if the value of the clock signal counted by the counter is higher than the duty cycle, a lower logic pulse may be generated. Thus, a conventional counter-based pulse generator may manage two time values to generate a pulse for controlling the duty cycle and the period.
However, many applications (e.g., related to DC motors such as step motor or servo motors) may require a multi-pulse having a plurality of different duty cycles within a single period. A multi-pulse may refer to a plurality of pulses with different duty cycles in the same period.
A multi-pulse may be generated with a conventional MCU by connecting a plurality of pulse generators in parallel with one another. As the number of pulses increases due to the multiple pulses in the multi-pulse via the parallel connection, a number of hardware devices in the MCU may likewise increase in proportion to the increasing number of pulses in the multi-pulse. Thus, again referring to FIG. 1B, as the number of pulses in the multi-pulse increases, additional counters 13, comparators 14 and 15, period value storage registers 11 and/or duty value storage registers 12 may be required to achieve the multi-pulse. As an amount of hardware increases in the MCU, a size of a chip may likewise increase.